Recently in Tampa, Lettuce Lake Park has a great boardwalk for nature photographers and while observing the Black-crowned Night Heron, I learned something.
This is just an observation guess… notice what the bird does while its beak is in the water. My guess is that by gently snapping into the water creates a vibration which will bring fish or other species from underwater to the surface.
The Little Blue Heron… super neat transformation this heron goes through. When they are juveniles their feathers are completely white with dusty bluish tips and going into their immature to an adult stage they begin molting; feathers start changing.
Like any wading bird, most spend a considerable amount of time preening.. and those are the best photo ops!